A cheap, convenient and universal TRNG based on mobile telephone photo for producing random bit sequence is proposed. To settle the problem of sequential pixels and comparability, three chaos-based approaches are appl...
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A cheap, convenient and universal TRNG based on mobile telephone photo for producing random bit sequence is proposed. To settle the problem of sequential pixels and comparability, three chaos-based approaches are applied to post-process the generated binary image. The random numbers produced by three users are tested using US NIST RNG statistical test software. The experimental results indicate that the Arnold cat map is the fastest way to generate a random bit sequence and can be accepted on general PC. The "MASK" algorithm also performs well. Finally, comparing with the TRNG of Hu et al. [Hu Y, Liao X, Wong KW, Zhou Q. A true random number generator based on mouse movement and chaotic cryptography. Chaos, Solitons and Fractals 2007. doi: 10.1016/***.2007.10.022] which is presented by Hu et al., many merits of the proposed TRNG in this paper has been found. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.
This paper presents the results of a user study which quantifies the relative and absolute quality of example-based texture synthesis algorithms. In order to allow such evaluation, a list of texture properties is comp...
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This paper presents the results of a user study which quantifies the relative and absolute quality of example-based texture synthesis algorithms. In order to allow such evaluation, a list of texture properties is compiled, and a minimal representative set of textures is selected to cover these. Six texture synthesis methods are compared against each other and a reference on a selection of twelve textures by non-expert participants (N = 67). Results demonstrate certain algorithms successfully solve the problem of texture synthesis for certain textures, but there are no satisfactory results for other types of texture properties. The presented textures and results make it possible for future work to be subjectively compared, thus facilitating the development of future texture synthesis methods.
Multilevel converters are capable of generating AC voltages with low-total harmonic distortion, applicable to power system applications such as penetration of renewable sources in an active network. These types of top...
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Multilevel converters are capable of generating AC voltages with low-total harmonic distortion, applicable to power system applications such as penetration of renewable sources in an active network. These types of topologies may require large number of switches and power supplies, having complex structures along with complicated control algorithms. Recently, a branch of multilevel converters is emerged, in which their 'reduced structure' topologies use lower number of devices compared to the available topologies. This study concentrates on classification of the branched 'multilevel converters' with a 'reduced structure' (MCRS) that lowers the number of semiconductor switches as well as their gate-drivers. Then, these classified structures are compared in terms of their number of power supplies and switches, the number of gate-drivers, breaking voltages of the switches and so on. This will pave the way for the introduction of a structure named B2 in the defined class B among the available MCRS topologies with the lowest number of power electronic devices;this structure is obtained by modifying the structure A2 in the defined class A. Moreover, design and simulation of a 31-level converter is analysed under optimal number of DC sources for all named structures. A laboratory prototype was implemented that verifies operation and performance of the suggested structure B2.
In order to meet the Quality-Of-Service (QOS) requirements of the VOD (Video-On-Demand) service, and, on the other hand, to maximize the system throughput (revenue), it is essential that the admission control algorith...
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In order to meet the Quality-Of-Service (QOS) requirements of the VOD (Video-On-Demand) service, and, on the other hand, to maximize the system throughput (revenue), it is essential that the admission control algorithm be carefully designed, In this paper, two new types of admission control schemes for the VOD service are proposed. They are the Enhanced strict Admission Control (ESAC) and the Probabilistic Admission Control. (PAC). In the ESAC schemes, we propose to use more statistics (of small amount and easily pre-calculated) than the peak frame size of the stored video information to strictly guarantee the QOS requirement and to achieve potentially much higher throughput. In the PAC schemes, we propose to use similar statistics ins used in the ESAC schemes to achieve even higher throughput at the cost of some small and controllable likelihood of lost/overdue data. The admission control problems are formulated as feasibility problems where different systems of simultaneous equations are considered. For each admission control scheme, if the corresponding system of simultaneous equations has a feasible solution, then admit the call request;otherwise, reject the call. Special structures of the systems are identified so as to facilitate the development of optimal real-time admission control algorithms. Efficient optimal algorithms are also proposed to calculate the minimal buffer requirement For a given performance objective.
In nuclear power plant construction scheduling, a project is generally defined by its dependent preparation time, the time required for construction, and its reactor installation time. The issues of multiple construct...
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In nuclear power plant construction scheduling, a project is generally defined by its dependent preparation time, the time required for construction, and its reactor installation time. The issues of multiple construction teams and multiple reactor installation teams are considered. In this paper, a hierarchical particle swarm optimization algorithm is proposed to solve the nuclear power plant construction scheduling problem and minimize the occurrence of projects failing to achieve deliverables within applicable due times and deadlines.
The semisupervised community detection method, which can utilize prior information to guide the discovery process of community structure, has aroused considerable research interests in the past few years. Most of the ...
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The semisupervised community detection method, which can utilize prior information to guide the discovery process of community structure, has aroused considerable research interests in the past few years. Most of the former works assume that the exact labels of some nodes are known in advance and presented in the forms of individual labels and pairwise constraints. In this paper, we propose a novel type of prior information called negative information, which indicates whether a node does not belong to a specific community. Then the semisupervised community detection algorithm is presented based on negative information to efficiently make use of this type of information to assist the process of community detection. The proposed algorithm is evaluated on several artificial and real-world networks and shows high effectiveness in recovering communities.
Focusing on novel database application scenarios, where data sets arise more and more in uncertain and imprecise formats, in this paper we propose a novel decomposition framework for efficiently computing and querying...
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Focusing on novel database application scenarios, where data sets arise more and more in uncertain and imprecise formats, in this paper we propose a novel decomposition framework for efficiently computing and querying multidimensional OLAP data cubes over probabilistic data, which well-capture previous kind of data. Several models and algorithms supported in our proposed framework are formally presented and described in details, based on well-understood theoretical statistical/probabilistic tools, which converge to the definition of the so-called probabilistic OLAP data cubes, the most prominent result of our research. Finally, we complete our analytical contribution by introducing an innovative Probability Distribution Function (PDF)-based approach, which makes use of well-known probabilistic estimators theory, for efficiently querying probabilistic OLAP data cubes, along with a comprehensive experimental assessment and analysis over synthetic probabilistic databases.
THE CHOKE ROUTER ALGORITHM PROVIDES AN APPROXIMATELY FAIR BANDWIDTH ALLOCATION AT A LOW IMPLEMENTATION COST. THE AUTHORS CONSIDER PERFORMANCE AND IMPLEMENTATION ISSUES ASSOCIATED WITH CHOKE, WITH PARTICULAR EMPHASIS O...
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THE CHOKE ROUTER ALGORITHM PROVIDES AN APPROXIMATELY FAIR BANDWIDTH ALLOCATION AT A LOW IMPLEMENTATION COST. THE AUTHORS CONSIDER PERFORMANCE AND IMPLEMENTATION ISSUES ASSOCIATED WITH CHOKE, WITH PARTICULAR EMPHASIS ON VARIABLE-LENGTH PACKETS.
One of the challenges confronting structural engineers in structural control is to find more efficient control algorithms to ensure better and more reliable control results to protect structures against the damaging e...
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One of the challenges confronting structural engineers in structural control is to find more efficient control algorithms to ensure better and more reliable control results to protect structures against the damaging effects of destructive environmental forces. In this paper, a simple control algorithm, namely the Predictive Instantaneous Optimal Control (PIOC) algorithm, is proposed by introducing a new state space form. Different from the classical ground acceleration-based control algorithms, this new control algorithm uses earthquake ground velocity as the input. Since the earthquake ground velocity is not at high frequency as compared with the ground acceleration, it can be predicted at certain time steps beforehand in real-time domain with higher accuracy. This ensures the synchronous execution of the proposed PIOC algorithm with real-time application of the control force. To capture the damaging effects during earthquake ground motions, the force analogy method is used to characterize structures responding in the inelastic domain. Numerical studies are performed to compare the structural response with and without control using both single degree of freedom and multi-degree of freedom structural models. Results show that the PIOC algorithm is effective in reducing the structural response under earthquake excitation. Copyright (C) 2006 John Wiley & Sons, Ltd.
For nonlinear differential-algebraic-equation subsystems, whose index is one and interconnection input is locally measurable, the problem of invertibility is discussed and the results are applied to the power systems ...
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For nonlinear differential-algebraic-equation subsystems, whose index is one and interconnection input is locally measurable, the problem of invertibility is discussed and the results are applied to the power systems component decentralized control. The inverse systems' definitions for such a class of differential-algebraic-equation subsystems are put forward. A recursive algorithm is proposed to judge whether the controlled systems are invertible. Then physically feasible. alpha-order integral right inverse systems are constructed, with which the composite systems are linearizaed and decoupled. Finally, decentralized excitation and valve coordinative control for one synchronous generator within multimachine power systems are studied and the simulation results based on MATLAB demonstrate the effectiveness of the control scheme proposed in this paper.
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